Control apparatus for synchronous meshing mechanism

Abstract

A control apparatus for a synchronous meshing mechanism that is equipped with a gear, a sleeve, a synchronizer ring, and a hydraulic actuator is provided. When it is determined that the sleeve and the gear have been rotationally synchronized with each other in an engagement transition period of the synchronous meshing mechanism, an electronic control unit with which the control apparatus is equipped sets a command pressure for the hydraulic actuator to an intermediate pressure that is lower than a meshing completion pressure. Besides, when meshing has not been completed even after the lapse of a predetermined time from a timing when the command pressure for the hydraulic actuator is set to the intermediate pressure, the electronic control unit sets the command pressure for the hydraulic actuator to the meshing completion pressure.

What is claimed is: 
     
       1. A control apparatus for a synchronous meshing mechanism, the synchronous meshing mechanism including
 a gear that is configured to fit a rotary shaft and is rotatable relative to the rotary shaft, 
 a sleeve that is provided unrotatable relative to the rotary shaft and movable relative to the rotary shaft in an axial direction of the rotary shaft, 
 a synchronizer ring that is interposed between the gear and the sleeve, and 
 a hydraulic actuator that applies a thrust force to the sleeve, the hydraulic actuator being configured to move the sleeve in the axial direction of the rotary shaft, and mesh a spline tooth that is provided on the gear and a spline tooth that is provided on the sleeve with each other after rotationally synchronizing the sleeve and the gear with each other via the synchronizer ring, upon moving the sleeve toward the gear side in the axial direction of the rotary shaft, the control apparatus comprising an electronic control unit that is configured to: 
 set a command pressure for the hydraulic actuator to an intermediate pressure that is lower than a meshing completion pressure at which the spline tooth of the sleeve and the spline tooth of the gear are meshed with each other, when it is determined that the sleeve and the gear have been rotationally synchronized with each other; 
 set the command pressure for the hydraulic actuator to the meshing completion pressure when the spline tooth of the sleeve and the spline tooth of the gear have been meshed with each other; and 
 set the command pressure for the hydraulic actuator to the meshing completion pressure when the spline tooth of the sleeve and the spline tooth of the gear have not been meshed with each other even after lapse of a predetermined time set in advance from a timing when the command pressure for the hydraulic actuator is set to the intermediate pressure. 
 
     
     
       2. The control apparatus according to  claim 1 , wherein the electronic control unit is configured to set the command pressure to the intermediate pressure assuming a value at which the spline tooth of the sleeve is able to move while jostling a spline tooth of the synchronizer ring and the spline tooth of the gear, after rotational synchronization of the synchronous meshing mechanism. 
     
     
       3. The control apparatus according to  claim 1 , wherein the electronic control unit is configured to set the meshing completion pressure to a value at which the spline tooth of the sleeve and the spline tooth of the gear are able to be forcibly meshed with each other, regardless of an influence of an oil temperature of a hydraulic oil in the synchronous meshing mechanism. 
     
     
       4. The control apparatus according to  claim 1 , wherein the electronic control unit is configured to:
 change the predetermined time in accordance with an oil temperature of a hydraulic oil; and 
 set the predetermined time longer when the oil temperature of the hydraulic oil is low than when the oil temperature of the hydraulic oil is high.